Rationality is even trickier. Is rationality simply internal consistency of choice? Obviously not, Sen replies. A person may very well be consistently moronic. Moreover, he argues, internal consistency is not even a necessary condition for rationality: when the reasoning involved in making choices is very complex, it is hard to even see what internal consistency would mean. Is rationality simply self-interest maximisation? No, for we can act on a variety of motives. It is question-begging to assume that self-interest is the only motive that is rational for us to have. Is rationality just pure and simple maximisation? Again, Sen argues, it is foolish to think of maximisation independently of a discussion of what it is that we wish to maximise. Any attempt to derive a purely formal definition of rationality is doomed to failure. As with freedom, rationality, the discipline of subjecting one’s choices to reasoned scrutiny, turns out to be a multi-faceted concept.